1. Field of the Invention
The present invention relates to the field of measuring devices for self-administration of a medicine, and in particular to a meter for electrically measuring and recording injection syringe doses.
2. Description of Prior Art
Electronic medical records have a significant advantage over paper medical records. With electronic medical records, health care providers and patients can better store, retrieve, and share medical information. Electronic medical records are particularly advantageous for the treatment of chronically ill patients who must self-monitor and self-inject medications on a daily basis. In therapies such as self-administration of insulin, human growth hormone, or other medications, patients themselves perform the injections and keep records.
Unfortunately, no adequate system exists for these patients to electronically record information about the doses they inject. That is because these injections are most commonly delivered with disposable syringes that have no mechanism for electronically recording the dose information. The patient is burdened with the task of injecting a dose and then manually recording the dose amount into a log.
Because of the frequency of such injections, often several times a day for diabetics, it becomes difficult to keep accurate records. Indeed, studies have shown that a patient's own records and recollections are often incomplete and inaccurate. Additionally, a patient may intentionally cheat while making self-recorded entries in an attempt to create a log that will please their doctor. In the long-term this makes patient monitoring extremely difficult and jeopardizes the therapy, possibly even endangering the patient's life.
Attempts have been made at developing electronic management systems for assisting patients in self-administered drug programs. For example, U.S. Pat. No. 5,019,974 issued to Andreas Beckers describes a hand-held recorder that can interface with a master computer. The recorder has a programmed computer, into which patient therapy information is entered via a keyboard, and a display for displaying treatment therapy guidelines to the patient. The recorder also includes a blood glucose meter connected to the programmed computer to help develop the therapy guidelines.
U.S. Pat. No. 5,307,263 issued to applicant on Apr. 26, 1994 describes a small, hand-held, microprocessor-based unit for self-care health monitoring. The unit has a program cartridge for controlling the operation of the unit, as well as switches for the patient to enter dose information. The unit also includes a blood glucose meter for monitoring the patient's condition.
Unfortunately, none of these inventions allows automatic electrical recording of the amount of medication injected. After injecting a dose, the patient must manually enter the dose information into a microprocessor-based system, using switches or keys. Although this is an improvement over keeping written records on paper, the effectiveness of the drug program is still limited by the patient's recollections and recordings, which are unreliable. Thus, there is a need for a device that provides an objective and accurate electronic record of injected dose information.
U.S. Pat. No. 4,853,521 issued to Ronald Claeys on Aug. 1, 1989 presents a programmable, intelligent reader unit which receives and records drug data using hand-held or fixed scanners. The scanners read bar codes in place on syringes, ampules, flow meters, etc. In addition, this intelligent reader allows the user to weigh a syringe before and after injection to determine and record the administered amount of medicine. Dosage data logged in this manner can be displayed or printed out in the form of a record.
While this apparatus comes closest to solving the problem, it involves many complicated steps of weighing syringes, scanning in bar codes, etc. These complex procedures as well as the high cost of the apparatus preclude effective home use. Additionally, the apparatus cannot be easily carried by the patient for measuring and recording doses while away from home. Thus, no cost-effective dosage meter exists that can electrically measure and record dose information from a syringe. Further, no electrical dosage meter exists that is easy to use and portable.